Interlocking schedules: the relationship between response and time requirements.
Interlocking FR-FI schedules create a unique pause-burst pattern that yoked VR or VI schedules alone cannot produce.
01Research in Context
What this study did
Rats pressed a lever on an interlocking FR 150 FI 5-min schedule.
The box also ran two yoked schedules: a VR and a VI.
Each rat lived all three schedules in rotation so the team could compare response patterns.
What they found
Yoked VR gave the fastest pressing. Yoked VI gave the slowest.
The interlocking schedule sat in the middle.
Only the interlocking schedule made clear break-and-run bursts: pause, then rapid firing.
How this fits with other research
BERRYMAELLIOTT et al. (1962) saw the same break-run shape earlier, but without the yoked controls. Rider (1977) adds proof that the pattern is tied to the interlocking rule, not just any FR-FI mix.
Cole (1994) later ran yoked VR vs VI without the interlocking link. Rates still differed, showing the gap is real, yet the unique burst pattern vanished. The two papers agree: yoking exposes schedule effects, but interlocking creates the special pause-run rhythm.
Rapport et al. (1982) moved the FR-FI idea to college students pressing buttons. People adjusted when the FR part rose, but they did not show the rat-style post-reinforcement pause. The break-run signature may be rodent-specific, so check your learner’s species before you bank on it.
Why it matters
If you build token boards or mixed schedules, know that interlocking rules can manufacture natural pauses and bursts. Watch for that rhythm when shaping new skills. If you only need high rates, a straight VR works. If you need steady low rates, lean toward VI. Test the interlocking blend when you want both: controlled waits followed by focused work bursts.
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Join Free →Try a short interlocking schedule—e.g., 10 responses OR 2 min, whichever ends first—and graph post-reinforcement pauses to see if the burst appears.
02At a glance
03Original abstract
Rats were exposed to an interlocking fixed-ratio 150 fixed-interval 5-minute schedule of food reinforcement and then to yoked variable-ratio schedules in which individual ratios corresponded exactly to the ratios of responses to reinforcement obtained on the interlocking schedule. After additional training with the interlocking schedule, the rats were exposed to yoked variable-interval schedules in which intervals corresponded to the intervals between successive reinforcements obtained on the second interlocking schedule. Response rates were highest in the yoked VR condition and lowest in the yoked VI, while intermediate rates characterized the interlocking schedule. Break-run patterns of responding were generated by the interlocking schedule for all subjects, while both the yoked VR and VI schedules produced comparatively stable local rates of responding. These results indicate that responding is sensitive to the interlocking schedule's inverse relationship between reinforcement frequency and responses per reinforcement.
Journal of the experimental analysis of behavior, 1977 · doi:10.1901/jeab.1977.28-41